IS CALF CIRCUMFERENCE ASSOCIATED WITH CLINICAL AND NUTRITIONAL OUTCOME IN OLDER PATIENTS?

ABSTRACT BACKGROUND: Previous studies have shown a relationship between calf circumference (CC) and outcomes in hospitalized patients. AIMS: To investigate the relationship between CC and clinical and nutritional outcomes in older in-patients (OiP) in a surgery ward. METHODS: This was a cross-sectional study with 417 OiP in a surgery ward. Clinical variables, anthropometry, and nutritional screening instruments such as subjective global assessment (SGA), mini nutritional assessment (MNA), and nutritional risk screening (NRS) were used in the investigation. The tests Pearson’s chi-square, Mann-Whitney, Kruskal-Wallis, and Spearman’s coefficient, and multiple linear regression analyses were used to review the factors associated with CC. RESULTS: Lower CC values were found in the age group 80 years and over (p<0.0001), presence of complications (p=0.0269), NRS (p<0.0001), SGA (p<0.0001), and MNA (p<0.0001). Gender (p=0.0011; partial R2=0.01151), age (p=0.0002; partial R2=0.06032), body mass index (p≤0.0001; partial R2=0.40820), and arm circumference (p≤0.0001; partial R2=0.11890) are variables that together were associated with CC. There was also a relationship between SGA (p=0.0166; partial R2=0.00605) and absence of complications during hospitalization (p=0.0047; R2=0.01154) with CC. CONCLUSIONS: Gender, age, body mass index, and arm circumference were jointly associated with CC, in addition to SGA and absence of complications. The CC is a relevant indicator for OiP in the clinical practice.


A QUEDA DA PRESSÃO PORTAL APÓS DESVASCULARIZAÇÃO ESOFAGOGÁSTRICA E ESPLENECTOMIA INFLUENCIA A VARIAÇÃO DO CALIBRE DAS VARIZES E AS TAXAS DE RESSANGRAMENTO NA ESQUISTOSSOMOSE NO SEGUIMENTO EM LONGO PRAZO?
Does the drop in portal pressure after esophagogastric devascularization and splenectomy variation of variceal calibers and the rebleeding rates in schistosomiasis in late follow-up?
Walter de Biase SILVA-NETO 1 , Claudemiro QUIRESE 1 , Eduardo Guimarães Horneaux de MOURA 2 , Fabricio Ferreira COELHO 3 , Paulo HERMAN 3 ABSTRACT -Background: The treatment of choice for patients with schistosomiasis with previous episode of varices is bleeding esophagogastric devascularization and splenectomy (EGDS) in association with postoperative endoscopic therapy.However, studies have shown varices recurrence especially after long-term follow-up.Aim: To assess the impact on behavior of esophageal varices and bleeding recurrence after post-operative endoscopic treatment of patients submitted to EGDS.Methods: Thirty-six patients submitted to EGDS portal pressure drop, more or less than 30%, and compared with the behavior of esophageal varices and the rate of bleeding recurrence.Results late post-operative varices caliber when compared the pre-operative data was observed despite an increase in diameter during follow-up that was controlled by endoscopic therapy.

Conclusion
variceal calibers when comparing pre-operative and early or late post-operative diameters.
The comparison between the portal pressure drop and the rebleeding rates was also not

Central Message
The vast use of nutritional screening instruments and anthropometry indicators that are routinely used in the hospital setting is already highlighted in the literature, especially when dealing with the assessment of the nutritional status of older patients.Although the use of calf circumference is not a new indicator, its application has been studied in particular in older in-patients.If we take into account that many older in-patients are bedridden, unable to walk, and therefore, unable to assess their body weight, this indicator could become a valuable method in identifying the nutritional status of these patients.
Anthropometry indicators included body mass index (BMI) (underweight, adequate or normal weight, and overweight) classified as recommended by Lipschitz 23 for older people; the cutoff point of 22 kg/m 2 identified patients with low body weight.Arm circumference (AC), triceps skinfold (TS), and arm muscle circumference (AMC) were evaluated according to previously defined criteria 5,15 and CC was classified according to the WHO 36 .
For the nutritional screening and assessment instruments, the nutritional status was classified by the subjective global assessment (SGA) 9 (well nourished and malnourished), and by the MNA 16 (eutrophic, risk of malnutrition, and malnourished), and the nutritional risk was classified by the NRS 20 (with nutritional risk and without nutritional risk).

Statistical analysis
To describe the characteristics of the population assessed, frequency tables were developed for categorical variables with absolute frequency (n) and percentage (%) values, and for quantitative variables, descriptive measures were obtained as mean, standard deviation, and median.To compare proportions, the Pearson's chi-square test or the Fisher's exact test was used, when necessary.For the comparison of continuous measures between two groups, the Mann-Whitney test was applied, and among three or more groups, the Kruskal-Wallis test.To verify the relationship between numerical variables, Spearman's linear correlation coefficient was used.To review the factors associated with CC, multiple linear regression analysis was adopted with the stepwise criterion for selecting variables.Multiple linear regression was operated aimed at identifying the variables associated with CC, but not to predict this result, by the assumption of cause and effect.Due to the transformation applied, the estimated parameters only served to direct the existing relationship and not for the calculation of predicted values.The transformation by ranks was chosen due to the absence of normality of the variables.The significance level adopted for the statistical tests was 5% 7,14,32 .

RESULTS
A population of 417 OiP was investigated, of which 64.3% (n=268) were male and 35.7% (n=149) were female.A total of 73.9% (n=308) was between 65 and 79 years of age and 26.1% (n=109) were 80 years and over.The rates of malnutrition by the instruments and the assessed indicators were different among them: 48.4% (n=202) were at nutritional risk according to the NRS; 14.6% (n=61) with malnutrition by MNA; 49.9% (n=208) at risk of malnutrition by MNA; 23.7% (n=318) with malnutrition according to SGA; and 26.1% (n=100) were underweight according to the BMI; the CC was 32.49±4.36cm (Tables 1 and 2).
Table 3 shows the correlation analysis results between CC and clinical and anthropometric variables, analyzed using Spearman's correlation coefficient.There was a significant correlation between CC and age in an inverse and weak way.A direct moderate to high-intensity relationship was also observed with BMI, AC, TS, and AMC (Table 3 and Figure 1).
There was a significant difference for CC between age groups (p<0.0001),presence of complications (p=0.0269),SGA (p<0.0001),NRS (p<0.0001), and MNA (p<0.0001).No difference was observed between gender (p=0.0689),type of disease (p=0.4076),surgery (p=0.5406), and death (p=0.4377)(Table 4).Lower values in CC mean or median were found in the group aged 80 years and over with clinical or surgical complications, at risk of malnutrition, or with malnutrition according to the NRS, SGA, and MNA.

INTRODUCTION
A ccording to the World Health Organization (WHO) 35 , the older adult population is growing rapidly worldwide and should reach more than 1.2 billion people in the year 2025.This growth could lead to increased demand for hospitals and health services in general.For this reason, the nutritional diagnosis and therapy of this population continue to be the focus of researchers' attention, such as the investigation of nutritional indicators for use in older in-patients (OiP), alone and in combination 1,10,13,19,22 .
The vast use of nutritional screening instruments and anthropometry indicators that are routinely used in the hospital setting is already highlighted in the literature, especially when dealing with the evaluation of nutritional status in older patients 6,17,22,25,28,30,39 .Just as it is already known that there is no defined gold standard for the assessment of OiP, many studies have compared different instruments for the actual nutritional diagnosis of this population 6,10,28,30,39 .
Analyzing the results and applicability of these nutritional evaluation methods in OiP, recent evidences 2,12 showed that the nutritional risk screening (NRS) and the mini-nutritional assessment (MNA) moderately agreed in the assessment of older adults 2 , and the NRS was considered a predictor of clinical outcomes 12 .Other studies have shown the estimation of calf circumference (CC) cutoff points as a screening tool for reduced muscle mass 18 .
Although the use of CC is not a new indicator, its application has been investigated particularly in OiP, as demonstrated in recent publications 4,11,27 .If we take into account that many OiP are bedridden, unable to walk, and therefore, unable to assess their body weight, this indicator could become a valuable method for identifying the nutritional status of these patients.
The objective of this study was to investigate the relationship between CC and clinical and nutritional outcomes in OiPs in a surgery ward.

Study design
This study was carried out in a university hospital that serves a representative population of adult and older adult patients in general, in a large metropolitan region.This was a cross-sectional and retrospective study, originally based on the selection of a population of approximately 500 OiP due to different diseases, admitted to a surgical ward.
The inclusion criteria for the participation were patients aged 65 years or older, who had undergone nutritional assessment procedure within the first 24 hours of admission, with diseases other than terminal, and with complete medical records in the institution.Patients hospitalized only for diagnostic investigation, those with dementia, and who remained in the hospital only for a period of less than 24 hours were excluded.After reviewing the inclusion and exclusion criteria, a total of 417 patients met the eligibility criteria for participation to be started within 24 hours after admission.The study was initiated after approval by the institution's Ethics and Research Committee (reference number: nº 3.587.982,CAAE 150277 19.0.0000.5481).

Methodological procedures and variables assessed
Data collection took place through a search in the medical records, assessing the variables gender, age, type of disease, comorbidities, surgery, complications, lymphocyte count 29 , and length of hospital stay.Next, all registries of nutritional status evaluation were collected from the medical records, such as anthropometry indicators and the instruments for screening and assessment.As observed in other studies 6,10,30,39,40 , different rates of malnutrition were verified by comparing the indicators and the nutritional assessment instruments used in the population examined 31 .The NRS was a sensitive tool for diagnosing patients at nutritional risk (48.4%); by clustering the malnourished patients with those at risk of malnutrition, according to the MNA, the total rate was 64.5%.These two instruments have been considered valid methods in the assessment of OiP 2,6,12 .
Due to the variability of the different values of malnutrition found in the assessment of OiP, several reports considered the use of many indicators and tools for nutritional diagnosis 24 .This issue was observed in a recent prospective study that used the same nutritional screening and anthropometry instruments, adopted in the present study, to investigate the nutritional status of older adults and the predictive value of those instruments in the mortality of OiP 38 .The study in question identified that both NRS and MNA could predict mortality, but only NRS was the independent predictor of mortality 37 .Another recent article also showed that only NRS was an independent predictor of unfavorable clinical outcomes in OiP 12 .The CC investigation and its association with mortality was also investigated in a recent systematic review and meta-analysis, showing that low   Table 5 shows the results of the multiple linear regression analysis of the study factors associated with CC.It was found that gender (p=0.0011;partial R 2 =0.01151), age (p=0.0002;partial R 2 =0.06032),BMI (p≤0.0001;partial R 2 =0.40820), and AC (p≤0.0001;partial R 2 =0.11890) are variables that together were associated with the CC measurement.There was also a relationship between the classification of nutritional status by SGA (p=0.0166;partial R 2 =0.00605) and the absence of complications during hospitalization (p=0.0047;R 2 =0.01154) with the CC measurement (Table 5).

DISCUSSION
The male gender and neoplastic diseases were prevalent in this investigation involving OiP.Although most older adult patients were aged between 65 and 79 years, there was a significant proportion of older patients aged 80 years and over.The CC mean or median values found herein are within the normal range, according to the adopted reference standard 34 .levels of CC were associated with a higher risk of mortality 33,36 ; such observations also point to the relevance of using the CC indicator in hospital clinical practice.Another important aspect is the presence of wasting syndrome and its associated factors in OiP, as observed in another work that indicated a high prevalence of this syndrome associated with clinical, biochemical, and nutritional variables, including CC 11 .In general, all anthropometric nutritional indicators can be used to assess nutritional risk in older adult patients 3 .
Our results revealed a significant relationship of moderate to high intensity between CC and other anthropometric indicators, which could suggest the use of CC to replace the other indicators for assessing the nutritional status in OiP.Another relevant finding of our study was the association between CC and age group, presence of complications, SGA, NRS, and MNA.It is important to emphasize herein that in a work that investigated the CC, laboratory tests, and NRS, CC was considered a simple, non-invasive method and an effective measure to predict the nutritional risk in hospitalized patients over 80 years of age 38 .
Our study found no association between CC and diseases.Other papers have pointed to CC as an easy measure capable of predicting falls in older adult patients on hemodialysis 27 , and as a valuable tool for predicting the risk of sarcopenia in OiP with hip fractures 4 ; also associated low CC values with frailty in diabetics older adult aged over 80 years 40 , and that CC showed good accuracy, sensitivity, and specificity for detecting malnutrition in both genders 3 .Another recent study that investigated the relationship between CC and AMC demonstrated that CC was associated with the risk of pneumonia 26 .
Our investigation showed that CC is an effective and easily applicable measure in the hospital setting.The most relevant findings of our investigation were the data observed by the multiple linear regression analysis for the study of factors associated with CC, in which it was possible to verify that the variables gender, age, BMI, and AC taken together were associated with CC and SGA and with the absence of complications during hospitalization.With these findings, it is possible to indirectly infer that this CC indicator may be better able to assess the nutritional status of OiP.The findings in our study are in line with other recent papers pointing to the relevance of using CC in older adults instead of other methods, especially if we consider those frequent situations of patients who are completely bedridden, unable to walk, and unable to measure body weight 21,36 .This study suggests even greater attention by healthcare professionals in treating the risk of sarcopenia in older adult patients, a situation already reported in the literature 8 .Under those conditions, CC indicator would be a very valuable method.
The strengths of the present study included the proper sample size, which represents more OiP in a surgical ward than those found in many other papers.In addition, several nutritional anthropometry indicators and nutritional screening were investigated.Another factor to be highlighted as a strong point of our investigation refers to the multiple linear regression that was applied with the purpose of identifying the variables associated with CC, but not for predicting this result, based on the assumption of cause and effect.Due to the transformation applied, the estimated parameters only served to direct the existing relationship and not for the calculation of the predicted values.Our study should be interpreted with some limitations, such as the fact that it was performed in a single center using a cross-sectional and retrospective design, which did not allow us to address other impacts.The most relevant aspects of this study are:  ABCD Arq Bras Cir Dig 2023;36:e1773 1.It was performed with 417 hospitalized patients in a surgical ward; however, it can be applied to other populations like those homebound and bedbound, unable to walk or stand, and therefore, unable to assess body weight.
2. The population herein is aged 65 years and older, male and female, with a high representation of older adults, which may benefit the current population of patients.
3. The CC indicator is easily applicable and can assist health professionals in assessing nutritional status of patients and risk of sarcopenia in the elderly.This article may be relevant to health professionals, and the topics that they are involved with and care about.This study suggests even greater attention by these professionals in treating the risk of sarcopenia in older adult patients.The CC is an effective and easily applicable measure in the hospital setting and may be better able to assess the nutritional status of OiP, especially in bedridden patients in a surgical ward.

CONCLUSIONS
Gender, age, BMI, and AC were all together associated with CC, in addition to sga and absence of complications; and CC is a relevant indicator in clinical practice in OiP.

Table 1 -
General characteristics of the studied population (n=417).

Table 2 -
General characteristics of the studied population (n=417).

Table 3 -
Spearman's correlation coefficient of calf circumference and clinical and anthropometric variables.

Table 4 -
Descriptive analysis and comparison of calf circumference with the variables studied.

Table 5 -
Results of multiple linear regression analysis for the study of factors associated with calf circumference.
R 2 model = 0.6165.*Estimated value; R 2 : coefficient of determination: partial; R 2 : proportion of response variability explained exclusively by the variable in question; R 2 model: proportion of explanation of the dependent variable by the variation of the independent variables that remained in the model.Stepwise criterion used for selecting variables; AC: arm circumference; BMI: body mass index; M: male; F: female.